Sugars measured enzymatically in a fasting overnight urine sample are not sensitive biomarkers of dietary added sugar intake in postmenopausal women.

This article evaluates the sensitivity of an enzymatic assay measuring urinary sucrose (U-Suc) and fructose (U-Fruc) in fasting overnight urine samples as biomarkers for detecting changes in added sugar intake among 30 postmenopausal women. Despite a significant increase in dietary added sugars after consumption of a sugar-sweetened beverage, urinary sugars measured enzymatically did not show corresponding significant increases, with U-Suc not correlating with dietary sucrose intake and U-Fruc only modestly associated with dietary fructose among participants with detectable urinary sugars. Validation using liquid chromatography-mass spectrometry (LC-MS) indicated that U-Suc measured by LC-MS was more sensitive and significantly associated with dietary sucrose and added sugar intake. The study concludes that enzymatic assays of urinary sugars from overnight samples are not sufficiently sensitive biomarkers for added sugar intake changes in this population, though urinary fructose may help differentiate low versus high added sugar consumers, and recommends further research using LC-MS methods.